RECOGNITION OF EARTHQUAKE-PRONE AREA (M \(\geq 5.0\) ) APPLIED FOR NORTH VIETNAM AND ADJACENCY
Keywords:North Vietnam, Morphostructural zoning, Pattern recognition, Seismogenic nodes
Seismogenic nodes capable of earthquakes with M\(\geq 5.0\) have been identified in the Northern Vietnam that exhibit the highest seismic activity over the Vietnam territory. Recognition objects - morphostructural nodes - have been delineated with the morphostructural zoning (MZ) method and their classification into seismogenic nodes and non-seismogenic ones was performed with the pattern-recognition.
With MZ we have compiled a morphostructural map (scale 1:1,000,000) for the study region. The map shows the hierarchical block-structure of the region, the network of boundary zones bounding blocks, and the loci of the nodes. A three-level hierarchy has been established for the blocks and their boundaries. The recorded M\(\geq 5.0\) earthquakes nucleate at the nodes delineated by MZ, i.e. ignoring the seismic record. Among all delineated nodes we recognized the seismogenic ones (D), prone to M\(\geq 5.0\) earthquakes, with the pattern recognition algorithm CORA-3. The performed recognition pinpoints a number of \(D\) nodes where events with M\(\geq 5.0\) have not been recorded to date.